^Feldman, J. (1992). "Review of Algebraic ideas in ergodic theory by Klaus Schmidt". Bull. Amer. Math. Soc. (N.S.). ج. 27: 189–191. DOI:10.1090/S0273-0979-1992-00295-1.
^Sucheston, Louis (1985). "Review of Amarts and set function processes by Allen Gut and Klaus D. Schmidt". Bull. Amer. Math. Soc. (N.S.). ج. 12: 306–312. DOI:10.1090/S0273-0979-1985-15387-X.